ABSTRACT
Indo-European, as we have seen, 1 had a rich variety of word-forms to express grammatical categories (number, case, tense, mood, etc.) as well as a large number of declensions for nouns and conjugations for verbs. It is by no means certain how these forms came into being, but it seems probable that at a very remote period the language consisted of full words carrying the basic sense and fixed in form, as well as a number of particles which indicated the relations between the full words. In the course of many centuries these particles coalesced with the full words to produce the richly inflected and apparently highly systematized language which comparative philologists have been able to reconstruct. This theory at any rate is consistent with the structure of nouns, adjectives, and verbs in the Indo-European languages. These can be analysed into a root which carries the basic sense (and may take on various ablaut forms; cf. Chapter 10, section B), one or more suffixes indicating the part of speech of the word and the declension or conjugation to which it belongs, 2 and an ending showing its actual function in the sentence. These elements are often far from obvious in the historical languages, as the following example shows:
IE. *dhogh-o-s, Gmc. *dag-a-z: Goth, dag-s, ON. dag-r, OE. dæg, OHG. tag.
